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// 假如有一张厚度为0.0001米的纸，折叠多少次可以超过10000米

// 递归
// let a=0.0001;
// let num=0;
// function fn(){
//     a*=2;
//     num++
//     if(a<10000){
//         fn();
//     }
//     console.log(num)
// }
// fn();



let arr=[
    { comment_id: 1, user_id: 43, comment_date: "04-23", comment_content: "蜡笔小新很好看!", parent_id: null },
    { comment_id: 2, user_id: 19, comment_date: "04-24", comment_content: "还不错哦!很好看", parent_id: null },
    { comment_id: 3, user_id: 17, comment_date: "04-25", comment_content: "我也感觉蜡笔小新很好看", parent_id: "1" },
    { comment_id: 4, user_id: 14, comment_date: "04-26", comment_content: "我感觉机器猫更好看一点", parent_id: "3" },
    { comment_id: 5, user_id: 13, comment_date: "04-27", comment_content: "好看,已三连!", parent_id: null },
    { comment_id: 6, user_id: 21, comment_date: "04-26", comment_content: "你是机器猫的粉丝吗", parent_id: "4" },
    { comment_id: 7, user_id: 14, comment_date: "04-27", comment_content: "是的,我是机器猫的粉丝", parent_id: "6" },
    { comment_id: 8, user_id: 23, comment_date: "04-27", comment_content: "我更喜欢白嫖!", parent_id: "5" },
    { comment_id: 9, user_id: 25, comment_date: "04-28", comment_content: "你个白嫖怪", parent_id: "8" }
]

function fn(temp){
    let arr1=[];
    for (let i = 0; i < arr.length; i++) {
        if(arr[i].parent_id==temp){
            arr1.push(arr[i])
            arr[i].child=fn(arr[i].comment_id)
        }
    }
    return arr1
}
const res=fn(null);
console.log(res)



// let arr1=[];
//     for (let i = 0; i < arr.length; i++) {
//         if(arr[i].parent_id==null){
//             arr1.push(arr[i])
//             for (let j = 0; j < arr.length; j++) {
//                 if(arr[i].comment_id==arr[j].parent_id){
//                     arr[i].child=[arr[j]];
//                     for (let p = 0; p < arr.length; p++) {
//                         if(arr[j].comment_id==arr[p].parent_id){
//                             arr[j].child=[arr[p]]
//                         }
//                     }
//                 }
//             }
//         }
//     }






// console.log(arr1)
// [
//     { comment_id: 1, user_id: 43, comment_date: "04-23", comment_content: "蜡笔小新很好看!", parent_id: null,child:[
//         { comment_id: 3, user_id: 17, comment_date: "04-25", comment_content: "我也感觉蜡笔小新很好看", parent_id: "1",child:[
//             { comment_id: 4, user_id: 14, comment_date: "04-26", comment_content: "我感觉机器猫更好看一点", parent_id: "3",child:[
//                 { comment_id: 6, user_id: 21, comment_date: "04-26", comment_content: "你是机器猫的粉丝吗", parent_id: "4" }
//             ]}
//         ]}
//     ]}
// ]
</script>
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